Copy protection rules, such as those defined by SMPTE ExCCI, generally do not take into account the existence of an authorized domain, in which devices owned by a single user can securely exchange content. Existing copy protection standards include states, such as “COPY ONE GENERATION,” “COPY NO MORE” and “COPY FREE,” which make sense when content is sent over an external unprotected interface, but would make a user's life very difficult when trying to apply these states to content that is shared by multiple devices in his authorized domain.
More user-friendly copy protection rules are needed for content when it is copied or moved inside a protected authorized domain. But the traditional (ExCCI-like) copy protection states still need to be defined for external interfaces that are still commonly used to communicate with off-the-shelf display devices (e.g., digital TV or computer monitor).
Furthermore, content users should be allowed to legally share content over protected (on-line or removable media) interfaces and this needs to be reflected in the content rights. It is rarely acceptable to allow a user to share pay content with everyone, so it is necessary to be able to specify a list of authorized domains within which content may be shared.
SMPTE ExCCI specification separates copy protection rules into digital and analog but does not address a concept of authorized domain.
Thus, the present invention is therefore directed to the problem of developing an automated method for controlling copyright protected content in a communications system.